Convertible chair.



NO MODEL.

PATENTBD NOV. 22, 1904.

E. L. THOMPSON.

CONVERTIBLE CHAIR.

APPLIOATION FILED JUNE 15. 1904.

Ira/emu l 'lwz'rc L Tkompawv conversion into the low carriage.

UNITED STATES Patented November 22, 190

PATENT OEEIcE- CONVERTIBLE CHAIR.

SPECIFICATION forming part of Letters Patent No. 775,388, dated November 22, 1904.

Application filed June 15,1904. Serial No. 212,629. (No model.)

citizen of the United States, and a resident of Baldwinsville, county of \Vorcester, State of Massachusetts, have invented an Improvement in Convertible Chairs, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention relates to chairs which can be converted at will into a high or low chair or carriage; and one of the objects of my present invention is the production of a chair of the convertible type which can be changed to an intermediate position between that of high chair and low carriage.

Another object of my invention is the production of novel locking means for holding the chair securely in its raised position and which will not interfere in any way with the The locking means is so constructed and arranged that it will be moved automatically into operative position when the chair is raised and automatically withdrawn out of the way when the chair is lowered for conversion into a carriage.

The novel features of my invention will be fully described in the subjoined specification and particularly pointed out in the following claims.

Figure 1 is a side elevation of a chair embodying one form of my present invention locked in its highest raised position. Fig. 2 is a rear elevation thereof. Fig. 3 is a side elevation of the chair lowered to form a carriage, showing the locking means as moved out of the way of the parts of the chair; and Fig. 4 is an enlarged sectional detail on the line 4 4, Fig. 2, looking toward the right, showing clearly the locking means.

The chair-body C, having a suitable seat C", is pivotally connected with the upper ends of two pairs of legs a and 7), crossed and having a pivotal connection at a the legs a being pivotally connected at a with the chairbody, at the back thereof, while the legs Z) are connected by links I) to the body at the front, truck-wheels 2? being mounted on the crosslegs near their lower ends. A transverse stop, shown as a rung b rigidly connects the outer legs 5 below their pivotal connection a to support the legs a and limit further movement of the cross-legs when they are spread to lower the chair and convert it into a carriage, as shown in Fig. 3, the wheels 2f then resting upon the floor or other supporting-surface. Other rungs, at 7) connect the pairs of legs at or near their lower ends to stiffen and strengthen the same.

I have arranged the chair herein shown to be capable of movement into two raised positions, with novel, simple, and effective means to lock it in either of such positions, and the locking means is so constructed as to moveautomatically out of the way when the chair is lowered, as shown in Fig. 3, and to move into operative position when the chair is raised. To this end a slitted bracket 1 is secured to the under side of the seat O and depends therefrom -at its back, and a forwardly-extended latch 2 is fulcrumed at 3 in the bracket, the rear end of the latch being shaped to form a finger-piece or handle 4, all clearly shown in Fig. 4. A stout coiled spring sis interposed between the handle and an extension 5 of the bracket, in which one end of the spring is seated, the spring normally acting by its expansion to lift the front end of the latch. The upper edge of the latter is shaped to present two upright shoulders 6 and 7, the outer one being preferably undercut or notched, as at 8, and beyond the shoulder 7 the upper edge of the latch is convexed or rounded, as at 9. A cooperating keeper is herein shown as a flat transverse metal bar 10, downturned at its ends at 11 and fulcrumed at 19. on the legs a above the pivotal connection a The keeper is adapted to engage either of the latchshoulders 6 or 7, as the case may be, and to control the swinging movement of the keeper it is pivotally connected at 13 with controlling-links 14, which in turn are fulcrumed at 15 on the legs 6 near their upper ends.

The weight upon the chair-body tends to spread the cross-legs, and this tendency is overcome by the locking means, for when the latch and keeper are in cooperative engagement the spreading of the upper ends of the cross-legs is resisted by the controlling-links 14, which hold the keeper against the latchshoulder. The greater the downward pressure upon the chair-body the more securely will the chair be locked in position.

In Figs. 1, 2, and 4 the chair is in its highest position, and to lower it to intermediate position the operator lifts the handle 4, de-

pressing the latch to withdraw the shoulder 6 from the keeper, whereupon the spreading tendency of the cross-legs acts to draw the latch and keeper in opposite directions, bringing the keeper up against the'shoulder 7 and again locking the chair, now in its intermediate position. (Not shown.) I prefer to notch this shoulder, as at 8, to receive the edge of the keeper 10 and positively prevent any slight accidental movement of the latch to free the keeper. Now if it is desired to lower the chair to the position shown in Fig. 3 the latch-handle 4 is again raised, while the chairbody is slightly lifted to cause disengagement of the keeper and the notched shoulder 7 and then the chair is allowed to descend as the cross-legs spread until the legs a restupon the stop 5 Fig. 3. As the legs spread the links 14 act to swing the keeper forward and clownward out of the way of the chair-seat (1*, while the spring 8 retains the latch in normal position. When the chair is raised, the links 14 swing the keeper 1O upward and rearward into engagement with the curved edge 9 of the latch, depressing the latter to cause it to slide under the keeper, so that the same may engage automatically one or the other of the shoulders 7 or 6, as may be desired.

The locking means is easily and readily controlled or operated manuallyfrom the back of the chair-bod y, and when the chair is raised from a lower to a higher position it is locked automatically in the higher position.

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a chair of the class described, the verticallyadjustable body, pivotallyconnected cross-legs to the upper ends of which the chair is pivotally connected, and locking means to maintain the chair in raised position, comprising a member mounted on the chair-body, and a cooperating member operatively connected with both pairs of cross-legs above their pivotal connection.

2. In a chair of the class described, the vertically-adjustable body, pivotally-connected cross-legs to the upper ends of which the chair is pivotally connected, and locking means to maintain the chairin raised position, comprising a spring-controlled, shouldered member mounted on the chair-body at the back and projecting forward thereunder, and a cooperating member operatively connected with both pairs of cross-legs above their pivotal connection.

8. In a chair of the class described, the vertically -adjustable body, pivotally -connected cross-legs to the upper ends of which the chair is pivotally connected, and locking means to maintain the chair in raised position, comprising a spring-controlled, doubleshouldered latch mounted on and beneath the chair-body at the back thereof, a cooperating keeper mounted to swing on one pair of cross-legs above their pivotal connection, and connections between said keeper and the other pair of legs, to move the keeper into and out of operative position when the chairis raised and lowered, respectively.

4. In a chair of the class described, the vertically adjustable body, pivotally connected cross-legs, transverse connections between opposite pairs of said legs, the chair-body being fulcrumed on the upper ends of one pair of cross-legs, links pivoted to the upper ends of the other pair and to the chair-body, a latch mounted on the latter, and means pivotally mounted on both pairs of cross-legs above their pivotal connection to cooperate with the latch and maintain the chair in raised position.

5. In a chair of the class described, pivotally-connected cross-legs, a chair-body ful- -crumed on the upper ends of one pair of legs,

links pivoted to the upper ends of the other pair of legs and to the chair-body,-a transverse keeper having its ends downturned and fulcrumed on the former pair of legs, a springcontrolled shouldered latch pivotally mounted on and beneath the chair-body and forwardly extended to cooperate with the keeper, and controlling-links pivotally connected with the keeper and with the upper ends of the front pair of legs, disengagement of thelatch and keeper permitting thecross-legs to spread and thereby lower the chair-body, closing of the cross-legs acting through the controllinglinks to etfect automatically cooperation of the latch and keeper.

6. In a chair of the class described, pivotally connected cross-legs, truck wheels mounted thereon near their lower ends,a transverse stop connecting one pair of legs to engage the other pair when the cross-legs are spread to lower the chair and form a carriage, a chair-bod y pivotally connected with the upper ends of the cross-legs, a transverse, swinging keeper mounted on one pair of legs to swing beneath the chair-body, a cooperating,

spring-controlled latch mounted on thelatter at the back, and controlling-links pivotally connected with the upper ends of the other pair of legs and with the keeper, to automatically move the latter out of the way when the chair is lowered to form a carriage and to move it into operative position with relation to thelatch when the chair is raised.

IIO

In testimony whereofI have signed my name i ELWIN L. THOMPSON. Witnesses W. P. ABBOTT, W. P. HAWLEY. 

